The idea of using multiple local models was studied in  [1]}, [2]}, [3]}. In this study, we mainly discuss the local latent factor models under the local low-rank assumption. The existing local latent factor models can be categorized into two types. First, LLORMA [4]} utilized multiple local matrices that represented local aspects of users, where local models overlapped with each other. The local collaborative ranking [5]} extended this idea to a pair-wise ranking objective.  [6]} proposed a local latent factor model using WMF [7]} under the same architecture. Although these models are capable of capturing local factors, they did not estimate global factors for all the users. Therefore, local models may not cover some users among the entire set of users.
